1. Field of the Invention
The present invention relates to an apparatus and method for correcting the convergence of a television, and more particularly, to a television convergence correcting apparatus and method for automatically correcting the convergence of a television in consideration of the terrestrial magnetism of a television location set by a user.
2. Description of the Related Art
In general, projection televisions, which are greatly affected by terrestrial magnetism, include a red (R)-cathode ray tube (CRT) 101, a green (G)-CRT 102 and a blue (B)-CRT 103 and display signals output from the respective CRTs on a screen 105 via a mirror 104, as shown in FIG. 1. Here, three color signals of R, G and B are combined at a position to produce an image on a screen. In order to accurately combine the signals, convergence correction is necessary.
FIG. 2 shows parts which perform convergence correction in the respective CRTs constituting a projection television.
First, correction signals for convergence correction are transmitted to an amplifier 203 via a filter 201 and an input matching portion 202 to be amplified and then output to a deflection coil 204 which is a convergence yoke. Then, convergence correction is performed with respect to light irradiated from a CRT. A feedback portion 205 receives some of the correction signals output to the deflection coil 204 through the amplifier 203 and allows the amplifier 203 to operate in a stable state.
According to the conventional technology, convergence correction is performed by forcibly setting correction values depending on the terrestrial magnetism of territories in which the products supplied by various manufacturers are used.
However, when the projection television is transferred from one territory to another territory, wherein each of the two territories have different terrestrial magnetism, the convergence correction performed by forcibly setting correction values for terrestrial magnetism of a pertinent territory may cause mis-convergence due to a difference in the terrestrial magnetism between the two territories, resulting in an unclear image.